WhenToBird

Astur cooperii · Accipitridae

When Do Cooper's Hawks Arrive in California?

Adult male Cooper's Hawk
Photo: Shirley Zundell, CC BY 4.0 via iNaturalist

The Cooper's Hawk is in California all year. It turns up on about 11% of checklists at its peak (late September) and on 6.6% in its quietest week (mid May).

When to look

PresentAll year
Peak weekSep 22-30late September
Quietest weekMay 15-21mid May

Best: late September. Here all year. Peak: on about 11% of California checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

Darker months: more checklists report it. Outlined: peak month.

0%5%10%15%Jan 1-7: 7.2% of 112336 checklistsJan 8-14: 7.1% of 85518 checklistsJan 15-21: 6.6% of 86488 checklistsJan 22-31: 6.7% of 116174 checklistsFeb 1-7: 6.9% of 75171 checklistsFeb 8-14: 7.2% of 84467 checklistsFeb 15-21: 7.4% of 105683 checklistsFeb 22-28: 8.3% of 83396 checklistsMar 1-7: 9.0% of 77470 checklistsMar 8-14: 9.4% of 75180 checklistsMar 15-21: 9.9% of 80770 checklistsMar 22-31: 9.9% of 114116 checklistsApr 1-7: 9.8% of 84057 checklistsApr 8-14: 9.2% of 83692 checklistsApr 15-21: 8.7% of 89242 checklistsApr 22-30: 7.8% of 114289 checklistsMay 1-7: 7.1% of 85728 checklistsMay 8-14: 6.3% of 91984 checklistsMay 15-21: 6.6% of 75478 checklistsMay 22-31: 6.7% of 106250 checklistsJun 1-7: 7.1% of 70051 checklistsJun 8-14: 7.1% of 67485 checklistsJun 15-21: 7.1% of 66269 checklistsJun 22-30: 7.3% of 79172 checklistsJul 1-7: 7.6% of 62877 checklistsJul 8-14: 7.6% of 60328 checklistsJul 15-21: 7.7% of 59705 checklistsJul 22-31: 7.4% of 83796 checklistsAug 1-7: 7.1% of 60215 checklistsAug 8-14: 7.0% of 60172 checklistsAug 15-21: 7.0% of 59877 checklistsAug 22-31: 7.8% of 89107 checklistsSep 1-7: 8.5% of 72000 checklistsSep 8-14: 9.2% of 71228 checklistsSep 15-21: 10% of 76808 checklistsSep 22-30: 11% of 100204 checklistsOct 1-7: 11% of 76571 checklistsOct 8-14: 10% of 80874 checklistsOct 15-21: 9.7% of 74581 checklistsOct 22-31: 9.4% of 97498 checklistsNov 1-7: 8.8% of 70851 checklistsNov 8-14: 8.5% of 72431 checklistsNov 15-21: 8.0% of 66767 checklistsNov 22-30: 7.6% of 94737 checklistsDec 1-7: 7.9% of 65393 checklistsDec 8-14: 7.9% of 67449 checklistsDec 15-21: 8.1% of 83421 checklistsDec 22-31: 7.5% of 124993 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Frequency is the share of complete checklists in California that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

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Where in California

Best counties

Share of checklists at the peak
  1. Orange CountyBest late September · 5728 checklists that week, 244,559 in all18%
  2. Los Angeles CountyBest late September · 10126 checklists that week, 410,235 in all18%
  3. Kern CountyBest late September · 1043 checklists that week, 47,774 in all17%
  4. San Bernardino CountyBest early October · 1538 checklists that week, 84,093 in all17%
  5. Ventura CountyBest mid March · 1965 checklists that week, 94,391 in all16%
  6. Sutter CountyBest late July · 81 checklists that week, 4,996 in all16%

Best spots

Share of checklists at the peak
  1. Kirby CoveMarin County, best early October · 190 checklists that week, 1,041 in all87%
  2. Buddy Todd Memorial ParkSan Diego County, best late June · 22 checklists that week, 1,409 in all87%
  3. Grant Park (La Loma del Cruz)Ventura County, best early October · 21 checklists that week, 151 in all79%
  4. California Botanic GardenLos Angeles County, best early July · 31 checklists that week, 2,014 in all77%
  5. Galileo ParkKern County, best late September · 37 checklists that week, 508 in all72%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In California, the Cooper's Hawk is most often listed on checklists started between 6 and 8 am (12% of those checklists).

0%5%10%15%12 am: too few checklists (1688) to judge1 am: too few checklists (1451) to judge2 am: too few checklists (1402) to judge3 am: too few checklists (1743) to judge4 am: too few checklists (4647) to judge5 am: too few checklists (32158) to judge6 am: 12% of 186053 checklists7 am: 12% of 444086 checklists8 am: 11% of 535846 checklists9 am: 9.0% of 486061 checklists10 am: 7.5% of 411130 checklists11 am: 6.3% of 325798 checklists12 pm: 5.6% of 269132 checklists1 pm: 5.5% of 244762 checklists2 pm: 5.9% of 235420 checklists3 pm: 6.3% of 232365 checklists4 pm: 6.2% of 208688 checklists5 pm: 6.5% of 146104 checklists6 pm: 5.7% of 96867 checklists7 pm: too few checklists (50942) to judge8 pm: too few checklists (14803) to judge9 pm: too few checklists (5561) to judge10 pm: too few checklists (3546) to judge11 pm: too few checklists (2092) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January7.2%7.1%6.6%6.7%
February6.9%7.2%7.4%8.3%
March9.0%9.4%9.9%9.9%
April9.8%9.2%8.7%7.8%
May7.1%6.3%6.6%6.7%
June7.1%7.1%7.1%7.3%
July7.6%7.6%7.7%7.4%
August7.1%7.0%7.0%7.8%
September8.5%9.2%10%11%
October11%10%9.7%9.4%
November8.8%8.5%8.0%7.6%
December7.9%7.9%8.1%7.5%

Neighboring states

  • Nevada: all year, most in fall, peaks late September
  • Utah: year-round, peaks mid September
  • Arizona: year-round, peaks early October
  • Oregon: summer visitor, peaks late September

Common questions

When do Cooper's Hawks arrive in California?
The Cooper's Hawk is in California all year. It turns up on about 11% of checklists at its peak (late September) and on 6.6% in its quietest week (mid May).
When do Cooper's Hawks leave California?
The Cooper's Hawk does not leave California: it is reported all year, from 6.6% of checklists in mid May to 11% in late September.
When is the best time to see a Cooper's Hawk in California?
The Cooper's Hawk is reported most often in late September, on about 11% of California checklists.
Where in California are Cooper's Hawks seen most often?
By county, Orange County, Los Angeles County, and Kern County have the highest peak reporting rates for the Cooper's Hawk (counties with at least 200 checklists).